1. Field of the Invention
The present invention relates generally to impact resistant cushions adapted for use in carrying cases and to carrying cases for securely transporting delicate instruments such as portable computers.
2. Discussion of the Prior Art
xe2x80x9cLaptopxe2x80x9d and xe2x80x9cNotebookxe2x80x9d portable personal computers have reduced size and weight and are conveniently carried and used while traveling. Manufacturers of portable personal computers strive to provide the smallest, lightest computer possible. Unfortunately, it is difficult to manufacture a small, light, portable computer rugged enough to withstand being dropped or otherwise subjected to shock loading. The small size of today""s portable computers leaves little or no internal room for shock absorbing materials to protect the vulnerable operating parts of the computer such as the LCD screen, the hard drive, the mother board, the various electrical connectors or the plastic outer case.
The effect of being dropped or hit is measured in terms of acceleration as compared to the earth""s gravitational pull; one xe2x80x9cGxe2x80x9d represents an acceleration (or deceleration) of thirty two feet/sec2. Each computer manufacturer""s design is different, and so there is no universally safe level of shock for portable computers. Manufacturers of hard drives typically specify that drives can withstand shocks in the range of seventy five to two hundred Gs. Manufacturers of LCD screens, on the other hand, guarantee their screens to withstand shocks of only as much as fifty Gs, a level reached by dropping a portable computer from a height of only six to seven inches. Since carrying cases for portable computers are usually hand held or hung from shoulder straps more than six inches from the ground, it is important that the cases provide adequate protection from the falls and bumps typically encountered in every day travel and use.
Many manufacturers of carrying cases for portable computers incorporate foam padding into their cases, the padding typically ranges in thickness from one half to about three inches. Foam padding will protect a computer, unless the padding is compressed completely (i.e., compressed to half the thickness of the foam pad). Thus, three inches of padding will protect the computer through a deceleration distance of one and one half inches. Tests have shown that in carrying cases provided with two inches of foam padding, the fifty G threshold (for LCD screens) is exceeded in drops from as little as eight inches in height.
A carrying case offering superior protection against shocks is disclosed in U.S. Pat. No. 5,217,119 and is marketed by PORT Computer Cases of South Norwalk, Conn. The case disclosed in U.S. Pat. No. 5,217,119 includes a suspension system using an elastic sling. The computer is protected within the sling through the full distance of the decelerating fall, without resting on a foam barrier. The empty space below the sling, to the bottom of the case, provides twice as much protection as an equivalent amount of foam rubber padding. U.S. Pat. No. 5,524,754, assigned to PORT, Inc., discloses a carrying case for a notebook computer having a suspension system elastically supporting and protecting the computer during transport and allowing the computer to be used without removal from the case. The disclosures of U.S. Pat. Nos. 5,217,119 and 5,524,754 are incorporated herein by reference, in their entireties.
While the carrying case structures of the ""119 and ""754 patents provide a high level of protection against shocks, it is desired to produce a computer carrying case exhibiting the same high level of protection from shocks while also allowing the user to adapt the computer support structure to accommodate a portable computer or other instruments of varying sizes, and allowing more economical manufacture.
Accordingly, it is a primary object of the present invention to support a portable computer (or other delicate instrument) of virtually any size or shape in a carrying case having a system of adjustable impact resistant cushions.
It is another object of the present invention to provide a luggage insert including a system of adjustable cushions specially adapted to conform to the shape of a portable computer.
It is yet another object of the present invention to provide a carrying case having an adjustable cushion system releasably fastened into the carrying case interior and positionable by the user, to accommodate computers having irregular sizes or shapes.
Yet another object of the present invention is to provide adjustable, impact resistant cushions using a reduced quantity of cushion material and permitting relatively easy and economical manufacture.
Another object of the present invention is to protect delicate instruments with one or more adjustable, impact resistant cushions having improved dynamic resistance to shock loading.
The aforesaid objects are achieved individually and in combination, and it is not intended that the present invention be construed as requiring two or more of the objects to be combined unless expressly required by the claims attached hereto.
In accordance with the present invention, an adjustable, impact resistant cushion for use in a carrying case or the like has a first pad including a compressible, substantially rectangular foam piece, formed of one or more foam blocks, covered with a pliable non-porous cover. The cover contiguously envelops the foam piece and includes an air flow controlling vent. Air escapes from the enveloped foam piece at a controlled rate through the vent when the foam material is compressed, and so the pad absorbs shock by providing velocity-dependent resistance to compression, wherein compression resistance force increases with increasing compression velocity, in the same manner as a shock absorber or dashpot. Preferably, the compressible foam piece is open cell urethane foam.
The adjustable impact resistant cushion also includes a second pad having a substantially rectangular compressible foam piece, preferably of a greater thickness than the first pad foam piece, and a pliable non-porous cover contiguously enveloping the foam piece. The second pad also includes an air flow controlling vent for controlling the escape of air to absorb shock and provide velocity dependant resistance to compression.
The first and second pads of the adjustable cushion are hingedly connected to one another by a flexible hinge segment of webbing or plastic, and the adjustable cushion includes, on a back surface, one or more releasable hook and loop type fastener elements.
In another embodiment of the adjustable impact resistant cushion of the present invention, the cushion has a substantially planar backing having a first elongate leg or resilient support member hingedly connected to a second elongate leg or support member. The first leg is connected at a distal end to the end of the first pad and hingedly connected at a second end opposing the distal end to the second leg connected at a distal end to the opposite end of the second pad, thereby forming a folded parallelogram of cooperatively hinged elongate pads and hinged elongate support members attached only at the distal ends. In the second embodiment of the cushion of the present invention, releasable hook and loop fastener elements are carried by the first and second legs of the planar backing.
Preferably, two adjustable, impact resistant cushions are used in a luggage insert (for insertion into a carrying case or other luggage) or are incorporated directly into the interior portion of a carrying case having a compartment with an interior surface covered with felt or loop material for attachment using complementary hook fastener arrays carried by the adjustable cushions or vice versa. An adjustable cushion may also carry one or more flexible tabs bearing hook fastener arrays and extending perpendicularly or outwardly from the cushion pad major axis. The cushions are readily positioned in cushion pairs at selected separations and angular orientations, thereby accommodating portable computers having different widths and shapes.
A luggage insert in accordance with the present invention provides impact resistant support for a portable computer or other delicate instrument and includes a container or receptacle portion having a compartment interior surface with loop fastener elements, felt, or another surface adapted to receive and hold the cushion hook fastener elements. Preferably, the insert is shaped substantially as a six-sided box having a front wall opposing a back wall and adjacent a top wall opposing a bottom wall which is also adjacent a left side wall opposing a right side wall. In the simplest embodiment, one pair of opposing walls (on the container interior or compartment) carry fastener elements (e.g., loops) for receiving complementary fastener elements (e.g., hooks) on the adjustable impact-resistant cushions. Each impact resistant cushion preferably includes a hinge segment and is placed with a first pad on a compartment side wall, for example, and a second pad on the bottom wall of the compartment and positioned substantially at a right angle to the first pad. The second impact resistant cushion is placed with a first pad on the compartment side wall opposing the side wall having the first impact resistant cushion first pad and has the second pad positioned substantially at a right angle thereto, on the bottom wall, substantially in line with the second pad of the first impact resistant cushion. The compartment has a lineal dimension (e.g., along the bottom wall) greater than the combined dimensions of the second pads of the first and second cushions. Using the fasteners on the flexible tabs carried by, preferably, at least one of the adjustable impact resistant cushions, it is possible to adjustably position the cushion with a first pad spaced apart from the side wall of the compartment while the second pad rests on the bottom wall, thereby accommodating a portable computer having a narrower outer case or housing. The carrying case receives and supports the user-adjustable cushions in a plurality of positions or angular orientations, thereby accommodating irregularly shaped delicate instruments or computers.
The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of a specific embodiment thereof, particularly when taken in conjunction with the accompanying drawings wherein like reference numerals in the various figures are utilized to designate like components.